1. Field of the Invention
This invention relates to a body on ships equipped with a streamlined profile, which is symmetrical in relation to its longitudinal center plane.
Bodies of this type experience a pressure reduction on the side away from the inflowing medium, and a pressure increase on the side facing the medium.
The result of this effect is that on the exposed end of the body, there is a pressure equalization caused by the medium flowing around the body, and a resulting high-energy wing-tip turbulence, a so-called negative vortex.
Such turbulence naturally wastes energy which, on objects moving in a liquid medium, as is the case in particular for ships, has a negative effect on the propulsion efficiency.
2. Background Information
On bodies designed as stabilizer fins, a solution has been proposed in the installation of means to reduce the above-mentioned negative vortex such as in German Patent No. DE-PS 1956032. These means consist of passages in the vicinity of the exposed end of the body, i.e. in the vicinity of the end cap, which run through the body diagonally, front to back in relation to the current direction. The medium enters these passages through a frontal opening and exits once again toward the rear.
This solution of the prior art may be effective in suppressing the above-mentioned turbulence, but in addition to reducing the inflow surface, it also causes problems from the point of view of fabrication and strength. On account of the flow in the passages, the solution of the prior art also encourages cavitation caused by abrupt changes in velocity, with its undesirable consequences, such as erosion of the material of which the body is made, underwater noises and vibration phenomena.